Create new folder in root level

Which "root level" are you referring to? You can create a folder anywhere you have permissions.

Well, usually doing anything from a root account is not recommended, so it depends on what you are doing that needs a folder outside a user folder. If you don't absolutely need root access, then placing a new folder in your user account should be all you need. If your script is just creating a folder somewhere, then there may just be a problem in the way you are getting or using the name.

I don't have Entourage, so the script doesn't want to open for me to look at it. The script author is talking about the root level of a folder, but it is unclear from the readme which folder that is. It can be the root level of the Microsoft User Data folder, or the Entourage folder, or even the Entourage scripts folder.

There really isn't any reason to create a folder for user documents at the root level of the startup disk (that is what the user folders are for), but you can use mkdir from the Terminal to make one, or create a new folder with the Finder and move it to where you want (you will need to authenticate as an admin).